Figure 2.

(a) Two-dimensional representation of the principal coordinates analysis based on Jaccard's similarities among AFLP fingerprints of genotypes: gray symbols represent members of the early bloom populations and black symbols represent members of the peak bloom populations. The plot shows how the subpopulation centroids shift over time, however, temporally subsequent subpopulations show considerable overlap. (b) Boxplot of beta-dispersion per subpopulation, based on the distances of each genotype to its respective group centroid. The thick line represents the median, the limits of the lower and upper box are 25 and 75 percentile, the bars extend to the most extreme values (excluding outliers), points indicate the position of putative outliers. The beta-dispersion of early and peak bloom subpopulation shows no significant differences in the low parasitized year 2008. However, the beta-dispersion of the peak bloom subpopulations in heavily parasitized years 2009 and 2010 is significantly larger than that of their respective early bloom subpopulation.